As shown in FIG. 1, a prior art paint roller 10 is used for applying paint and composed of a hand grip 11, a rotary shaft 12, a roller cover fastening device 13 fastened pivotally with the rotary shaft 12, and a roller cover 14 fastened with the device 13.
The roller cover fastening device 13 consists of a first cover body 13A, a second cover body 13B, and a plurality of metal wires 13C. The roller cover 14 has one side which is in contact with a retaining portion 13D of the outer peripheral surface of the first cover body 13A. The metal wires 13C are capable of being deformed by the inner wall 14A of the roller cover 14. The roller cover 14 is fastened with the fastening member 13 by the elastic force of the metal wires 13C such that the roller cover 14 is capable of swiveling along with the fastening member 13 in relation to the shaft 12.
The metal wires 13C are vulnerable to the metal fatigue. The roller cover 14 may be made without precision or sphericity. As a result, the axial displacement of the roller cover 14 is prone to take place. In addition, the roller cover 14 may be even detached. Moreover, the prior art paint roller 10 is further not effective in design in that the paint is prone to infiltrate into the fastening member 13 via a circular interstice 14B located between the outer peripheral surface of the second cover body 13B and the inner wall 14A of the roller cover 14, or via another side of the roller cover 14. The paint deposited in the fastening member 13 may splash unexpectedly through the circular interstice 14B at the time when the prior art paint roller 10 is at work.